1. Field of the Invention
This invention relates to a process for preparing guanidine. The term "guanidine" used herein is intended to imply free guanidine, guanidine salts, and guanidine derivatives such as guanylurea and salts thereof. And if not specially described, the concentrations of guanidine described hereafter are the converted values as free guanidine.
2. Description of the Prior Art
In the industrial production of guanidine, guanidine is usually prepared from dicyandiamide and ammonium nitrate or other ammonium salts. In order to raise the efficiency of production, the production process must be conducted under high temperature conditions or under high temperature and high pressure conditions. When ammonium nitrate is used as a starting material and treated under such severe reaction conditions, there is a great danger of explosion.